#include<stdio.h>
int main()
{
	int arr[] = { 1,2,3,4,8,7,5,4,3,2,1,6,7,8 };
	int i = 0;
	int sz = sizeof(arr) / sizeof(arr[0]);
	int count = 0;
	for (i = 0; i < sz; i++)
	{
		int j = 0;
		count = 0;
		for (j = 0; j < sz; j++)
		{
			if (arr[i] == arr[j])
				count++;
		}
		if (count == 1)
			printf("%d\n", arr[i]);
	}
	return 0;
}